Urea derivative of amidonaphthol sulfonic acid and method of making same.



lIO

A lTE STATES PATENT OFFICE.

ADOLF ISRAEL AND RICHARD KOTHE, OF ELBERFELD, GERMANY, ASSIGNORS TO THE FARBENFABRIKEN OF ELBERFELD COMPANY,

OF NEW YORK, N. Y.

UREADERIVATIVE 0F AMIDONAPHTHOL SULFONIC ACID AND METHOD OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 656,646, dated August 28, 1900.

Application filed April 21 1900. Serial No. 11,239. (No specimens.)

To aZZ whom it may concern.-

Be it known that we, ADOLF ISRAEL and RICHARD KOTHE, doctors of philosophy,

Our invention relates to the production of a new urea derivative of amidonaphthol sulfonic acid, being an alkaline salt of an acid having the following formula:

The process for producing this body consists in causing phosgene (C001,) and a substance adapted to absorb hydrochloric acid to act on beta -amido-alpha,-naphthol-beta -sulfonic acid. A condensation of two molecules of the above-named amidonaphthol sulfonic acid with one molecule of phosgene takes place under evolution of two molecules of hydrochloric acid,the above-defined urea derivative being thus formed according to the following equation:

The new urea derivative thus obtained may be employed for the manufacture of valuable azo dyestuffs.

In carrying out our new process practically we can proceed as follows, (the parts being by weight:) 23.9 parts of beta -amido-alpha naphthol-beta,-sulfonic acid are dissolved in about from four hundred to four hundred and fifty parts of water under the addition of a watery solution containing twenty-four parts of sodium carbonate, (Na CO Into the solution thus obtained a current of gaseous phosgene (C001,) is slowly introduced at ordinary temperature under continuous stirring. The reaction is finished when unchanged amidonaphthol sulfonic acid does l l I I \Q/K/I not precipitate any more in a test portion on the addition of an excess of diluted hydrochloric acid, and the acid liquid thus obtained is not changed by the addition of a small quantity of sodium nitrite.

The new urea derivative is precipitated by the addition of common salt filtered ofi,

pressed, and dried. The sodium salt of the.

responding calcium salt represents faintlyreddish leaves, readily soluble in hot and less soluble in cold water. These salts are prepared by the addition of solutions of BaCl or OaOl to a watery solution of the sodium salt of the said urea derivative. On boiling the urea derivative with the twenty fold quantity of hydrochloric acid of twenty per cent. it dissolves, and after boiling for some hours the urea derivative is decomposed and the regenerated bet-a -amido-alpha -naphtholbeta -sulfonic acid is precipitated.

The new urea derivative is capable of combining with one and likewise with two molecules of diazo compounds, thus furnishing valuable azo dyestu ifs.

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is

1. The process for producing a new urea derivative of amidonaphthol sulfonic acid by first dissolving a mixture of beta -amido-alpha -naphthol-beta -sulfonic acid and sodium carbonate in water, secondly introducing into the solution thus obtained a current of gaseous phosgene (C061,), and finally isolating the resulting urea derivative, substantially as hereinbefore described.

2. As a newarticle of manufacture the urea derivative of beta amido alpha naphtholbeta -sulfonic acid which in the form of the free acid has the following formula:

\ l I l OH OH 4 and which in-the form of the sodium salt is afaintly-reddish crystalline powder being capable of combining with one and likewise with two molecules of diazo compounds, being readily soluble in water, very difficultly in alcohol, and which on boiling for some hours with the twenty-fold quantity of hydrochloric acid of twenty per cent. is decomposed and beta -amido-alpha naphthol-beta -sulfonic acid is regenerated, substantially as hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witmesses.

ADOLF ISRAEL. RICHARD KOTHE.

\Vitnesses:

OTTO KONIG, HANS ScHAnnE. 

